Severe and Short Interval Fires Rearrange Dry Forest Fuel Arrays in South-Eastern Australia
Christopher E. Gordon,
Rachael H. Nolan,
Matthias M. Boer,
Eli R. Bendall,
Jane S. Williamson,
Owen F. Price,
Belinda J. Kenny,
Jennifer E. Taylor,
Andrew J. Denham,
Ross A. Bradstock
Affiliations
Christopher E. Gordon
Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
Rachael H. Nolan
Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
Matthias M. Boer
Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
Eli R. Bendall
Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
Jane S. Williamson
Science, Economics and Insights Division, New South Wales Department of Climate Change, Energy, Environment and Water, Parramatta, NSW 2150, Australia
Owen F. Price
Centre for Environmental Risk Management of Bushfires, Centre for Sustainable Ecosystem Solutions, University of Wollongong, Wollongong, NSW 2522, Australia
Belinda J. Kenny
Science, Economics and Insights Division, New South Wales Department of Climate Change, Energy, Environment and Water, Parramatta, NSW 2150, Australia
Jennifer E. Taylor
School of Behavioural and Health Sciences (NSW), Australian Catholic University, North Sydney, NSW 2060, Australia
Andrew J. Denham
Science, Economics and Insights Division, New South Wales Department of Climate Change, Energy, Environment and Water, Parramatta, NSW 2150, Australia
Ross A. Bradstock
Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
Fire regimes have shaped extant vegetation communities, and subsequently fuel arrays, in fire-prone landscapes. Understanding how resilient fuel arrays are to fire regime attributes will be key for future fire management actions, given global fire regime shifts. We use a network of 63-field sites across the Sydney Basin Bioregion (Australia) to quantify how fire interval (short: last three fires 10 years apart) and severity (low: understorey canopy scorched, high: understorey and overstorey canopy scorched), impacted fuel attribute values 2.5 years after Australia’s 2019–2020 Black Summer fires. Tree bark fuel hazard, herbaceous (near-surface fuels; grasses, sedges <50 cm height) fuel hazard, and ground litter (surface fuels) fuel cover and load were higher in areas burned by low- rather than high-severity fire. Conversely, midstorey (elevated fuels: shrubs, trees 50 cm–200 m in height) fuel cover and hazard were higher in areas burned by high- rather than low-severity fire. Elevated fuel cover, vertical connectivity, height and fuel hazard were also higher at long rather than short fire intervals. Our results provide strong evidence that fire regimes rearrange fuel arrays in the years following fire, which suggests that future fire regime shifts may alter fuel states, with important implications for fuel and fire management.
